Progress in Superconductivity and Cryogenics (한국초전도ㆍ저온공학회논문지)

The Korean Society of Superconductivity and Cryogenics (한국초전도저온학회)
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Investigation on helix type labyrinth seal to minimize leakage flow of cryogen for rotating superconducting machines

  • Yubin Kim (Department of Smart Manufacturing Engineering, Changwon National University) ;
  • Kihwan Kim (Department of Smart Manufacturing Engineering, Changwon National University) ;
  • Seungcheol Ryu (Department of Smart Manufacturing Engineering, Changwon National University) ;
  • Hojun Cha (Department of Smart Manufacturing Engineering, Changwon National University) ;
  • Seokho Kim (Mechanical engineering, Changwon National University)
  • Received : 2024.03.04
  • Accepted : 2024.03.28
  • Published : 2024.03.31
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Abstract

High-temperature superconducting rotors offer advantages in terms of output-to-weight ratio and efficiency compared to conventional phase conduction motors or generators. The rotor can be cooled by conduction cooling, which attaches a cryocooler, and by refrigerant circulation, which uses circulating liquid or gas neon, helium and hydrogen. Recent work has focused on environmental issues and on high-temperature superconducting motors cooled with liquid hydrogen that can be combined with fuel cells. However, to ensure smooth supply and return of the cryogenic cooling fluid, a cryogenic rotational coupling between the rotating and stationary parts is necessary. Additionally, the development of a sealing structure to minimize fluid leakage applicable to the coupling is essential. This study describes the design and performance evaluation of a non-contact sealing method, specifically a labyrinth seal, which avoids power loss and heat load caused by friction in contact sealing structures. The seal design incorporates a spiral flow path to reduce leakage using centrifugal force, and computational fluid dynamics (CFD) simulations were conducted to analyze the flow path and rotational speed. A performance evaluation device was configured and employed to evaluate the designed seal. The results of this study will be used to develop a cryogenic rotational coupling with supply and return flow paths for cryogenic applications.

Keywords

Acknowledgement

This research was supported by National R&D Program through the National Research Foundation of Korea(NRF) funded by Ministry of Science and ICT(2022M3I9A1073187) , (No. 2019R1A5A808320112)

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